44 Correspondence — J. Coggin Brown. 



Geology of the Papakaio District," by G. H. Uttley ; " A Comparison 

 of the New Zealand and "Western North American Cretaceous and 

 Tertiary Formations," by P. G. Morgan. (October 17, 1917) 

 "Natural Regions in New Zealand," by E. K. Lomas. (May 15, 

 1918) "The Geomorpliology of the Coastal District of South- 

 western Wellington," by C. A. Cotton. (June 19, 1918) "Notes on 

 the Post-Tertiary History of New Zealand," by J. Henderson. 

 (July 17, 1918) "The Origin of the Amuri Limestone and Flint 

 Beds," by J. Allan Thomson; "Notes on the Geology of Stephen 

 Island," by J. Allan Thomson; " Perrao-Carboniferous or Maitai 

 Rocks of the East Coast of the South Island," by P. G. Morgan. 



At the meeting a resolution was adopted expressing appreciation, 

 of the palfeontological work of the late Mr. Henry Suter; and also 

 a resolution expressing appreciation of the palseontological work of 

 the late Dr. E. A. Newell Arber, in particular of his work on the 

 Mesozoic floras of New Zealand. 



OOZRIRESlPOIISriDElSrOIE. 



THE GENESIS OP TUNGSTEN OEES. 



Sik, — It is to be regretted that Mr. R. H. Rastall, when compiling 

 his very useful summary of our present knowledge of the genesis, 

 mode of occurrence, and mineral associations of the ores of tungsten, 

 the first part of which appeared in the Geological Magazine for 

 May, 1918, had not before him the results of later researches than 

 those of Dr. Bleeck regarding the ore-deposits of the Tavoy district 

 of Lower Burma, as his results have not been accepted entirely by 

 later workers. 



For the past three years a party of the Geological Survey of India 

 has been working in Tavoy, and the district has also had the 

 advantage of the presence of several enthusiastic private geologists. 

 The Geological Survey party has examined most of the lodes which 

 occur, investigated their contents as carefully as possible, and mapped 

 the boundaries of the granite and the sedimentary series into which 

 it is intruded. Our results may be summarized briefly : — 



1. Dp to the present time not a single specimen of columbite has 

 been found. 



2. Tourmaline does not occur in the ore mineral association, and is 

 not a normal constituent of the granite. The occurrence of tourmaline 

 pegmatites is known, but they are not associated with the ore- 

 bearing zones and do not contain either wolfram or cassiterite. 



3. Fluor spar is a widely distributed lode mineral, but it is only 

 found in insignificant quantities. 



4. Topaz is known to occur in one alluvial cassiterite deposit, and 

 to-day, after three years of detailed field investigation together with 

 petrological and chemical determinations in the laboratory, has only 

 been found in situ once, in conjunction with fluor spar bordering 

 a lode which contains relatively large quantities of pyrite, molyb- 

 denite, cassiterite, and very little wolfram. There are over one 

 hundred producing mines in Tavoy district alone, and the lodes 

 examined must amount to many hundreds. 



